Startup Equity Dilution Calculator
See how a funding round dilutes founder and existing shareholder ownership.
About the Startup Equity Dilution Calculator
Enter the pre-money valuation, the amount raised, your ownership before the round and any new option pool. The calculator gives your ownership after the round, the investors' share, the post-money valuation and what your stake is worth on paper.
Investors' share is the amount raised divided by the post-money valuation (pre-money + raise). Everyone else is diluted proportionally. An option pool created before the round comes out of existing holders' share.
The formula
Investor % = raise ÷ (pre-money + raise); your new % = old % × (1 − investor % − pool %)
Worked example
Raising 2m at an 8m pre-money valuation; you own 60%; a 10% option pool
- Post-money: 10m; investors get 2 ÷ 10 = 20%
- Your share: 60% × (1 − 20% − 10%) = 42%
- On paper 4.2m, down from 4.8m because of the pool
Questions people ask
Does dilution lose value?
Not necessarily; a smaller slice of a bigger, funded company can be worth more.
What about SAFEs and convertible notes?
They convert at the round, adding further dilution; model them separately.
Can I avoid the pool diluting only founders?
You can negotiate a smaller pool or ask that it's created after the round, so investors share the dilution.